I often spend weekends and whole weeks away from home during the summer months and therefore an auto-feeder has become a necessity.

When looking for a suitable one I have a couple of requirements on top of reliability. The way the hood over my tank is constructed I have no way of utilising any of those that are fixed to the side of the aquarium. Which leaves me quite limited in choice.

One of my restrictions is the amount of room (height) inside the hood. The other thing I look for is how well they can deal with the condensation that occurs. In the past I’ve been away for a week and come home to find half (or more) of the food in the drum a congealed mess and the fish ravenous.

Some years ago I stumbled on one made by Resun; easily and cheaply available via the internet (under a tenner). Apart from its low height it will allow 4 times to be set and each of those can be programmed to deliver 1 or 2 lots of food by the simple means of rotating the drum. The drum lid is a simple flap located on the top of the drum which closes by gravity thereby fending off the condensation.

Occasionally a piece of food – just a flake or a crisp, would get trapped by the flap and would then get sticky due to the condensation and eventually lock the flap shut. But this didn’t happen often it was just something I was aware of.

My one complaint about this device was the programming. It was awkward. Not something that you could easily remember and required that unmanly task of actually reading the manual.

When I moved away from cover-glasses the positioning of this feeder became a bit of a problem and occasionally I knocked it into the water. The Resun didn’t like a dunking. Just the merest contact with water would short out the electronics which would need fixing by leaving the device on a radiator for a day.

Then came the day when it had one dunking too many and its reliability failed. I would have probably ordered another one if I hadn’t seen a different type on display at dealer that I chanced upon after visiting a friend.

This one – Eden 901 was a much more substantial piece of kit, with a substantial price too; £31. Apparently (sales talk) Eden products were a big hit at a recent Product Show but I’ve yet to see them on sale anywhere else. Looking them up on the internet I found out that they are an Italian firm.

This device, low in height and high in technology appealed to the nerd in me. It too has 4 programmable feeding times but each one can be instructed to give 1, 2 or 3 feeds - again by the simple method of rotating the drum. The programming is simple and memorable so I’ve only had to read the manual once. However, the means of combating condensation are far more elaborate.

The food container is yet another drum but it is housed inside the body of the devise which has a seal. When the timer kicks in the drum is mechanically pushed out from the body where it then completes its programmed number of rotations and is then retracted back into the body of the devise where the seal prevents the incursion of condensation.

I’ve had this thing in continuous operation for two months to test it and so far there hasn’t been any gumming up of the food or faults in its operation.

I suspect if height wasn’t a problem I would have discovered that there are other equally good bits of kit on the market but the Resun has served me well and the Eden is looking promising.

I've had a few problems in the past too. Came home once after a few days away and found loads of uneaten food all over the tank and the feeder empty. Had no idea how long it had been there. Lucky not to have had any problems.

But the Resun units never let me down in that way. So far so good on the other one.